Under a contract from the National Cancer Institute we have established methologies to serially passage epithelial cells from the colon of normal rat. The objective of the proposed research is to isolate proliferative cells from the normal human colon and develop optimum nutritional conditions for their continuous propagation in serum supplemented and in serum-free medium. Proliferative cells from the normal human colon will be isolated by the Ficoll gradient procedure and sequential time dissociation of the colonic mucosa in a tissue dissociation solution. Primary cultures will be established in medium supplemented with serum, hormones, and/or growth factors. The epithelial nature and colonic origin of the cell cultures will be determined by histochemical, ultrastructural, biochemical and immunocytochemical methods. The epithelial colonies will be passaged by the penicylinder procedure. Once the serial passage cultures in the serum containing medium have been established, attempts will be made to define conditions to propagate the cells in serum-free medium.